a) The payback period for this investment occurs in the 5th year.
b) The NPV for this investment is -$1.54 million.
The payback period describes the time it takes for an investment to generate an amount of income or cash equal to the cost of the investment.
The payback period does not consider the time value of money.
The Net Present Value (NPV), which discounts future cash flows with the cost of capital, is a more sophisticated method to evaluate an investment.
The payback period:
Year 0 (initial investment): -$10.9 million
Year 1 (release year): +$4.5 million
Year 2: +$1.9 million
Year 3: +$1.9 million
Year 4: +$1.9 million
Year 5: +$1.9 million
The cumulative cash flow:
Year 0: -$10.9 million
Year 1: -$10.9 million + $4.5 million = -$6.4 million
Year 2: -$6.4 million + $1.9 million = -$4.5 million
Year 3: -$4.5 million + $1.9 million = -$2.6 million
Year 4: -$2.6 million + $1.9 million = -$0.7 million
Year 5: -$0.7 million + $1.9 million = $1.2 million
Thus, the payback period is in the 5th year.
The NPV can be calculated using the formula:
Formula
-

= net present value
= the net cash inflow during the period t
= the discount rate or cost of capital
= time of the cash flow
= the initial investment
Cost of capital = 10.2% = 0.102 (10.2/100)
NPV = -$10.9 million + $4.5 million / (1 + 0.102) + $1.9 million / (1 + 0.102)^2 + $1.9 million / (1 + 0.102)^3 + $1.9 million / (1 + 0.102)^4 + $1.9 million / (1 + 0.102)^5
NPV = -10.9 + 4.09 + 1.66 + 1.41 + 1.19 + 1.01
NPV = -$1.54 million